Hob-testing machine.



c. G. OLSON & J. n. RICHER.

HOB TESTiNG MACHINE.

APPLICATIIINv FILED MAR. I9. iQII.

Patented Jan. 22, 1918.

4 SHEEIS-SHEET I.

c. 's. OLSON & 1. a. mum.

HOB TESTING MACHINE.

APPLICATION FILED um. 19. rsn.

Patnted Jan. 22, 191&

4 SHEETS-SHEET 2- I 75' t! v flwa x C. G. OLSON & J. R RICHER.

HO B TESTING'MACHINE.

APPLICATION FILED IIAR. 19.1911- Patented Jan. 22,1918.

4 suzns-succr 3.

c. e. OLSON & 1. R. -RICHER.

HOBTE'STING MACHINE.

APPLICATION FILED IAN. l9- 19H.

Patenfed Jan. 22,1918.

4 SHEETS-SHEET 4;

a a k m t e invention, we

UNITED STATES PATENT ()FFIOE.

cm s. OLSON AND .rosnrn a. mouse, or cnrcnoo, 112m iirc' risgfAasiti 'r'riij aa 'rd "amass 'roor. wonxs, or cnrcaoo, rumors, a coaronarron 081131118018.

HOB-TESTING MACHINE.

Specification of Letters Patent.

Patented Jan. 22,1918.

Application and mm. 19, 1911. Serial 110. 155,055.

To all whom it may concern.-

Be it known that we, CARL G. OLSON a citizen of the United States, residing at Chicago, Cook county, Illinois, and Josnrn It. Brenna, a subject of the King of Sweden, having declared his'intention to become a citizen of the United States, residing in the same city, county, and State, have invented a certain new and useful Improvement in Hob-Testing Machines, of which the following is a specification.

()ur invention rel. tes and while it may be used for testing the ac curacy of various objects, such as gear wheels and pinions, it is particularly useful for testing the accuracy of hobs used in ear cutting. For the purpose of explaining have shown it as in the act of testing a hob. In general the machine consists of an arbor for rotating the hob, a

to testing machines,

carriage traveling lengthwise of the hob,

and a recording indicator mounted on the carriage. The indicator has a record sheet upon which marks are made by a suitable stylus which is in turn, is operated by a contactor which enters between the teeth of the hob and moves the indicator arm to one side or the other of a median line in case there is any inaccuracy in the hob. Means are provided for causing the carriage to travel in accordance with the pitch of the helically arranged teeth of the hob, and other means are provided for bringing the contactor into and out'of engagement with the teeth of the hob. Means are also provided for feeding the record sheet and for ruling the record sheet so that tributory objects will appear as the descripti'on proceeds. We accomplish our purposes'by the mechanism illustrated in the accompanyingairawings, in which: j igure 1 is a general front view of theirssembled. machine showing, a hob in position to be tested.

Fig. 2 is a vertical on the line 22, Fig. 1.

operated by an arm, which, I

I held projected by, a spring 9 section of the machine:

Fig. 3 is a section of the ind cating mechanism taken on the line 3 3, Fig. 2.

Fig. 4 is a side view looking at the right side of the upper portion of Fig. 3.

Fig. 5 is a sectional view taken on the line 5-4), Fig. 2. It shows the lead screw and the carriage which it causes to travel.

Fig.6 is a to viewof one end of the lead screw and of t e change speed gear which transmits movement from the lead screw to the hob drive mechanism.

Fig. 7 is a sectional view on the line 7-7,

.Fig. 6, showing the change speed gearing.

Fig. 8 is a perspective of the contactor, the

I indicator arm, and their connecting parts.

trate the invention, the main frame 1 has a tail stock 2 provided. with a tail stock center 3 for supporting one end. of the arbor 4.

The arbor is rotatable and carries the hob 5 which is to be the subject of the test. The construction of the arbor may be varied, but in the present case has a rigid collar 6 at one end which forms an abutment for one end of the hob, and at the other end is threaded for receivin a nut 7 by which the hob is removably held securely upon the. arbor. The tail stock slide 8 is longitudinally movable n the tail stock and .is normally shown in dotted lines in Fig. 1. An operating lever 10 for retracting the tail stock center is pivoted upon the pin 11 in the tail stock and has an arm 12, shown in dotted lines in Fig. 1. The free end of this arm engages the tail stock slide for retracting it when the arbor is to be placed or removed. i

A head stock 15 is also mounted upon the main frame and carries a spindle 16 which .is provided at one end with a'head stock center the arbor 4. The spindle also carriesa dog 17 for entering the adjacent end of p 18 which engages a face plate 19, which is .fastened by a "set screw 20 or other appropriate means to the arbor. Hence whenthe spindle rotates, it drives the arbor and with it the hob itself.

The powerfto drive the s indle of the head is by t e lead screw 22 r h ui a l fir ng, which is Pr ably best sh wnin ,igsil. .6 and 7. In a type of gearing selected for illustrative purpose, a member 23, which'mai quadran has a hub 24 w ich encircles spindle 20 and permitsit to rock about it as an axis The uadrant is provided with a handle 25 by which it ma be manipulated. It also has a slotted link 56 which receives a screw stud 27 which screws into the head stock and holds the quadrant in the position to which it may be adjusted. The quadrant has two slotted guides 28 and 29 which support and'guide the studs 30 and 31 resgectively. The stud 30 forms an axle for t e gear wheel 32, while the stud 31 forms an axle for the alternate gear wheels 33 and 34. A gear wheel 35 is rigidl fastened to spindle 20 for rotatin it. A ead screw bracket 37 is bolted to t e main frame and forms a journal bearing for a counter shaft 38 to which is fastened a gear wheel 39.

As suggested in Figs. 6 and 7, the gearwheels 39, 32, 33, 34 and 35 constitute a train for transmitting power from shaft 38 to spindle 20, Any desired speed ratiomay be obtained by substituting different size gear wheels in the train.- This maybe accomplished by temporarily lowering the quadrant, sliding the studs30 and 31 to proper ositions and otherwise proceeding as will be readily understood by' those familiar with the use of change speed gearin the lead screw 22 an in ordinary lathes. Power is transmitte from the'l'ead screw 22 to the counter shaft 38 by gear wheels 41 and 42, wheel 41 being fastened to the lead screw and wheel 42 to the counter shaft. The lead screw is journaled at one end in the said bracket 37 and at the other end in a bracket 45, which is bolted or otherwise fastened in the main frame. The lead screw is rotated by means of a hand wheel 46, shown in Fig. 1. r

The indicating mechanism' roper mounted in a carria e 48 guided by statio ary ways 49, best s own in Fig. 2.- .These ways are arranged arbor 4. A lead screw nut 50 in which the lead screw works is fastened to the carriage 48 with the result that when. the lead screw is rotated the carria e is caused to travel in one direction or the other, according to the directionin which the, hand wheel is 'rotated.. has transverse ways 51 for dicator housing 52. According to the present design,'th1s housing is .in the form of a castin having a long boss 53 at the top for gui in 7 boss is'split at one side, and the two parts are held together by a cap screw 56. By tightening or' loosening this screw, the amount of friction between the'ca'si'ngand the housing may be regulated.

The indicator casi is a hollow c linder having a frame 58. at its uglier end or cartying the recording mec be termed a' (parallel tothe axis of The carriage guiding the inthe indicator casing 55.- This' "the actuating arm transmitted to the indicating arm 72 by a In the present instance, said frame is bifurcated and held in position by a set screw 59, as best shown in Figs. 1 and 2. The housing 52 is made to slide toward and from the axis of the hob through the agency of a hand lever 61 which. is inned or otherwise fas-v toned to the rock shaft 62 journaled in said housin A rocker arm 63 is pinned or otherwise rigidly fastened to said rock shaft and has an annular head 64 formed at its outer end, as best shown in Figs. 2 and 5. This head is held between two abutment pieces 66 and 67. One of these, the piece 66, screws into the carriage 48 and hence is adjustable, although otherwise rigidly held in the carriage. The abutment piece 67 is yieldable, being backed up by a compression spring 68. This spring is comparatively strong and does. not yield except in cases of emergency. The construction and operation is such that when the hand lever 13 rotated it produces a corresponding movement in the rock shaft 62 and rocker arm 63.' As the head 64 of said arm is, under normal conditions, held fast between its two abutmentpieces, it acquires no movement except a rotary one and consequently, the housing aturnin spring 70 shown in Fig. 5. This is here s own as a helical spring encircling the rock shaft. One end of the spring is fastened to the rock shaft and the other end to the housing 52.

Within the tubular casing 51 is an indieating arm 72. This arm projects out through the -upper end of the casing and near its lower end is pivotally supported by laterally projecting trunnions 3. These arts are shown in perspective in Fig. 8. he trunnions bear in cups 74 which screw into the side of the casing as shown is Fi 2. An actuating arm 75 is provided wit similar trunnions 76 which bear in cups 77 screwing into the side of the 'casin below the cups 74. At the lower end of t e actuating arm is a contactor having in the present case a spherical head 78 anda threaded shank 79 w ich screws into the lower end of the actuatin arm. It is not essential that .the head 0 the contactor be s herical, the idea being that the head she I' be "of such form as to conveniently fit between the teeth and contact the two adjacent surfaces simultaneously. It will be evident that any lateral dis will be re ectedin a corresponding lateral displacement'of the opgosite, up r and of uch disp acement'is connecting block having at itsends so lacement of the contactor head The result-L i gee some casesipoinumontact with-the two arms.

The: knife .wfitl rinto sockets. which, in the; instant example are formed by bars 83 bolted tdiitheaarms. The 'parts are held in engagement "1 by; a a spring 84 1 which is here Sl'lOWIlgiB the;form ofE-a-: sprin wire clip, the .ends 1i whereo engage the bacis up close zto thezconnecting..block and there is no lostymotion. 1 1 The, trunnions', or pivotal points on the arms 72 and 75 are so located on saidarms rthatthe; ovement of the upperflend of: the; indicatingmarm 72 will be muchsgreaterjv, hen of= theihead 7 8. 1n the form; herec shown, the ratio' of movement is 100 topLfi Thus, a-nwinaccuracy of a onehousandthwofwan in htin thethob will produce awdisplacement;ofa tenth of an inch at thelupperjendiof the indicating arm.

We will now describe the devices by which a permanent (record; maybe made of theaccuracy oriinaccuracy of the 1 hob:

,A.. record sheet; or strip is stored in a roll; 91; in ahousi'ng-QZ, as'sliown in Fig. 2. The sheet passestover ga roller 93 journaled inthe branchestof the bifurcated indicator 7 frame158. .J It then ,passesdown between this roller; and another one .Qiwhich is alsojourfastens. the bar tot cator casing which I carries the rollers and naled on vframetand creates traction by belnfi .1 constantly 1. urgedv toward its companion ro er. by spr ngs .95, shown in dotted line,

Fig. 2. If desired thesurface of roller 95 mayfc0vered:;.with blotting paper. By preference, these rollers. are geared together to insure feeding of the paper. The record sheet is:,;advanced automatically by mechanism detailedvin; Figs. 3 and 4. he roller 93 istprovided .with aratchet wheel 97 so, that when:tl epratchetisrotated a step the roller will be rotated a {corresponding amount.j pawl 98 isfulcrumedon a pin 99 supported ona housing 100 carried at the upper'fend of a. bar 101. This has a slot 102 in itsvlowerportion throughwhich a cap screw 103 passes. The screw taps into the base of the housingffl and hence adj ustablv e'housing.

ratchet wheel, moves relatively to said housing every tim e mi reading is taken, relative movement between ,the: pawl and the ratchet wheelisj th'usprovided. {The pawl is urged towardvthe ratchet wheel by a spring 105,

shown indottedt lines in. Fig.4. The normal position of thelpawl is-regulated by an adj ustable. step 106, which 1 is here shown in pawlwill be in engagement with the wheel forlafiording line, or, in

a of the bars. hatsthe arms are always held r 0rd sheet. As the ind1- and Will consequently cause itto rotate as I the wheel axis moves up.

The record is produced on the record sheet by ast lus 110 mounted at the upper end of thein icating arm 72. Styluses of various types may be, employed, but in the design shown, a fountain stylus is employed having an ink reservoir 111. This device traces a line on the sheet which will have a lateral component in case the contactor head 78 is moved laterally. I

A pre-ruled record sheet may be employed if desired, but I have found that greater accuracy may be obtained by placing a ruling device adjacent to the stylus, for b this arrangement, the stylus is correlate with the lineson the sheet and accurate tracking of. the sheet is rendered uimecessary. Furthermore, by this arrangement the sheets may vary in width without affecting the accuracy of the record. The ruling devices selected a for illustration are best shown in Figs. 2, 3 and 4. They consist of a ruling roller 115,

the marking crests whereof are preferably one-tenth ofan inch apart. This roller is hollow and held between two adjusting nuts 112, which screw onto a threadedrod 113 supported in the branches of the frame 58.

This provides for lateral adjustment of the.

inking roller so that it will always rule the basic reference line in juxtaposition to the neutral position of the stylus. Adjacent to it, and also journaled in said frame is an inking roller 116. The rulin roller contacts boththe inking roller and t e surface of the sheet and thus traces parallel reference lines thereon.

In. operation, when a test is to be made,

the hob is so placed and adjusted on the arbor 4 that when the contactor head 78 is lowered to engage the'right end of it, said head will enter squarely between two teeth and when in contact with them, both will hold the indicator arm 72 in central or neutral position so that the'stylus 110 will overlie the median or reference line onthe rec- For illustration, let it be .assumed that this reference line is the one identified by the numerals 120, Fig. 9. Let it alsobe assumed that under these conditions, the stylus will be at the starting station Where the arrow at a would intersectlthe reference line. The machineis now set, it being understood that the operator has pre' viously so selected the change speed gears 32, 33, 34, 35 and during the test to after another to the indicator, the indicator carriage will keep pace.

When the operator is ready to take a reading, lie rotates he hand wheel 46 to bring a new pair, of hob teeth beneath the indicator. When this has been done he pulls the indicator lever 61 toward him and causes the contactor to approach -39 that as the hob rotates present one pair of teeth 7 the hob. If the 13 hob is accurate at this point, the contactor .will sufler no lateral displacement and the stylus will remain accurately on, the said reference line 120. The operator then releases the indicator lever and the indicator automatically rises and returns to normal position. During this rise the awl 98 is in engagement with the ratchet 9 and causes the rollers 93 and 94 to rotate and advance the paper one step beneaththe stylus. As the stylus has not been laterally displaced it will, during this advance of the trace a line coincident with the re erence line 120. The paper has now advanced so that the stylus will be opposite to the arrow at b, Fig, '9. f

The operator then repeats the process, first rotating the hand wheel and lowering the indicator.

Let it assumed that the contactor on this occasion enters between teeth that are faulty in some respect, for example, lateral] out of true position, the helical pitch 0 the hob being too small or' w1 great. The. contactor in approachin e laterally displacedand will -pro uce a corresponding ateral movement of the, stylus. Suppose the inaccuracy on the. hob to be two and one-half one-thousandthsof an inch and that it is such as toproducea movement of the stylus toward the right. The stylus will move across the paper to they second line to the right. When the operator releases the indicator lever and permits the indicator to rise, the paper will have had traced upon it by the stylus a vertical line located between the second and third ruled lines to the right of the reference or median line 120, as shown in Fig. 9. This line will reach to a point opposite the arrow at 0. Thus, a graphic record is roduced, and

y by building the parts to sea e and inking the paper to scale, the operator will be able to determine at a glance at what points and to what extent, .i any, the hob is inaccurate.

It may be that in some cases the contactor descends on the top of a tooth, or}

for other, reason, downward movement 0 the indicator is obstructed. In such event, the operator in pulling down upon the indicatorlever 61 will not wreck or strain the parts, for the s ring 68 will permit the abutting piece 6 to yield and permit the lever to rock without producing a corresponding movement in the indicator eas Tt will be seen from the foregoing that the machine makes an accurate record of the formation of a hob and performs its work in elficient and simple manner. 7

We claim as our invention:

1. A hob testin machine having hob supporting means a 'pted to rotate the hob, a contactor having a rounded head, an indicator arm actuated by-said contactor, and a aper,

-' progressing teeth 0 from t e hob, sal

nausea support whereon said contactor and arm are mounted to move rectilinearly in a direction substantially toward and from the axis of the hob whereby the said rounded head may be caused to enter between two hob teeth and contact both of'them simultaneously.

2. A machine for tedaing hobs and the like, comprehending means forrotatably' supportmg the hob, a carriage travelin past it, an in icator 'on said carriage Ian means for .c'ausin said carriage to travel in harmon wltllll the lead of the helically arranged, ho teet 3. A hob testin machine, consisting of an, arbor for rotatab y supporting the hob, an indicator carriage trave ing past it, 'indicat: ing mechanism on said carriage movable toward and from the hob, and a lead screw for causing the carriage to travel, saidjlead screw being .geared to the arbor for making the carriage keep Face withthe helically the hob; 4. A hob testin machine, consisting of an arbor for rotatalfiy sup rting the hob, an indicator carriage trave mg past it, indicating mechanism on said carri movable toward and from the hob, ,sai indicating mechanism having an indicator arm and a contactor for actuating said arm, said contactor havingv a roun ed head for entering 96 between two adjacent hob teeth and contactving them both simultaneously, and a lead screw for causing the carriage to travel, said screw being geared'tosaid arbor.

- 5. A machine for testing toothed objects 100 having means for $31 porting the object to be tested, a contactor av a rounded head for entering between an simultaneously contacting two of the teeth of said object, 7

an indicator arm actuated by said contactor, a housin forsu porting-said-contactorand arm, an contro in means for moving said housin toward and fromsaid object, said contro ing means including an arm connected at one end to said housing and at the other end held at a fixed distance from the object to betested. 1

6. A hob testing machine having means for supportin the hob, a traveling carriage, indicator mec anism onsaid carriage comrising an indicator arm and a contactor,

or actuating it, said contactor being adapted to contact the teeth of the hob, su porting means for the contactor, an in icator' arm movable on the carria toward and from the hob, and controlling means for movin said sup orting means toward and controlling means including an arm connected at one end to the carriage and at the other to the said supportmeans.

A hob testing machine having means for supportin the hob, a traveling carriage, indicator mec anism on said carriage comprising an indicator armand a contactor for 18 2 contactor havin actuating it, said contactor being adapted to'contact' the teethof thehub, supporting means for the'contactor, an indicator arm movable on the carriage toward and from 5 the hob, controlling means formoving said supporting meanstoward andfrom the hob,

said controlling means including an arm connected at one end to the carriage and at tlleother end to the said" supporting means,

and a spring for-urging said arm to'move the supporting means away from the-hob.

8. A hob 'testingmachine having means forsupporting thehob, a carriage traveling past it parallel to its axis, a tubular. casing supported upon said carriage and movable toward and from the hob, an indicator a rm having trunnions hearing on the inside of the casing, and a contactor having trunnions also bearing on the inside of the casing, said a head adapted to contact I the teeth of the ob, said contactor and indi cating arm being connected together wherebymotion of one is transmitted to the other.

9. A hob testing machine having means i for supporting the hob, a carriage traveling parallel to the hob axis, indicating mecha: nism on said carriage movable toward and from the hob, and controlling means for thus moving the indicating mechanism, said controlling means comprising a hand operated arm articulately connected at one end to the indicating mechanism and at the other end to the carriage.

10. A hob testing machine having means for supporting the hob, indicating mecha nism movable toward and from the hob,

a'carriage for supporting said indicating mechanism, said carriage traveling parallel to the axis of the hob, and controlling means 40 for moving the indicating mechanism toward and from the hob, said controlling means comprising. an arm articulately connected at one end to the indicating means and at the other end to the carriage, the connection at one end of said arm beingyieldable when subjected to unusual strain.

11. A hob testing machine having means for supporting'the hob, indicating mechanism movable toward and from the hob, a

carriage for supporting said indicating mechanism, said carriage traveling parallel to strain.

12. A hob testing machine having means a for supporting the hob, indicating mecha nism movable toward and. from the hob,

a carriage for supporting said indicating t5 mechanism, said carr age traveling parallel abutment piece.

to the axisofthe hob, and controlling means for moving the indicating mechanlsm toward and fromthe hob, said controlling means comprising an arm pivoted at one end to the indicating means and at the other end held between two abutment pieces mounted inflthe carriage, one of said abut- 13. Ahob testin machine having means for supporting the ob, a carriage traveling parallel to the hob axis, indicating mechanism mounted on said carriage and movable toward and from the hob, a hand-operated rock shaft. journaled in said indicatin mechanism, a rocker arm ri idly fastene to said. shaft, a yieldable a utmentpiece mounted. in said carriage in position to en gage the free end of said rocker arm, anda second abutment piece, screwin into said carriage in line with the yieldab e abutment piece and en aging the opposite side of the free end of t e rocker arm.

14. In a machine for testing the accuracy of configurated objects, a main frame for supporting the object to be tested, an in-- I dicating arm having a contactor for actuating it, movable controlling means supported on saidjmain frame for moving' said con tactor, toward and from the object to. betested, a record sheet, a stylus on said arm for marking said sheet, a roller on said con 0 trolling means for advancing said sheet, and means, part of which is connected to the roller and part tothe movable controlling means for advancing the roller every time the controlling means completes a cycle in 106 moving the contactor toward and from the object tobe tested.

15. In a machine for testing the accuracy of configurated objects, a main frame forsupporting the object to be tested, an in- 110 dicating arm having a contactor for actuating it, movable controlling means supported on said main frame for movin said contactor toward and from the o ject to be tested, a record sheet, a styluson said arm for marking said sheet, a roller on said controlling means for advancing said sheet, a ratchet wheel connected to said roller for rotating it and advancing the record sheet, and'a pawl supported upon the main frame and cooperating with said ratchet for rotating it and the roller every time the controlling means makes a round trip.

16. In a hob testing machine, a main frame for supporting the hob, an indicating arm having a contactor for actuatin it, movable controlling means supports on said main frame for moving said contactor toward and from the hob, a record sheet, a stylus on said arm for'marking said sheet,130

- I supportin a roller vancin said sheet, a ipaw carried "by said main rame for rotatingj'the ratchet, and an adjustable stop for regulating the normal 5 position of said ratchet. 4 v

17. In a hob testi machine, a main frame'for supporting movable controlling means sup rted on said main framefo'r moving sa1 I contactor toward and from the hob, a record sheet, a I

, stylus on said arm for marking said sheet,

a roller on said controlling means for both the record sheet beneath. the stylus an advancing said sheet, and a pawl orig-riled by .said main frame for rotating the ra et.

18.- A hob testing machine com rising a.

vmain frame for supporting the ho an inon said controllin means for ade hob, an indic'ating arm having a contactor for actuating it, r

dicating arm having a contactor for'actuating it, movable controlling means sup rted 'on sald main frame for movin sai contactor-toward and from the ho a record sheet, a stylus on said arm for marking said sheet, a roller mounted on said controlling means for advancing said sheet, a ratchet wheel for actuat' said roller, a pawl cooperating with sai ratchet for actuating it,

and a bar adj ustabl supported upon the main frame for regu at the normal position of the pawl, to there y permit the ma-. chine to accommodate hobs of different sizes. 4

In witness whereof we have hereunto subscribed our names.

CARL G. OLSON. JOSEPH R..RICHER.. 

